Esto es similar a los códigos de estado HTTP 200 (de 200 a 299). Esos códigos de estado "200" significan que de alguna manera hubo un "éxito" en el request.

Los códigos de estado en el rango de 400 significan que hubo un error por parte del cliente.

¿Recuerdas todos esos errores de **"404 Not Found"** (y chistes)?

errors.app.db.already.updated = Es posible que ya haya sido actualizado por otro proceso. Por favor, inténtelo de nuevo.
errors.app.db.already.exists = Los datos ya existen. Por favor, inténtelo de nuevo.
errors.app.double.submit.request = Es posible que esta solicitud ya se haya procesado. Por favor, inténtelo de nuevo.

```console
// Create an env var MY_NAME in line for this program call
$ MY_NAME="Wade Wilson" python main.py

// Now it can read the environment variable

Hello Wade Wilson from Python

// The env var no longer exists afterwards
$ python main.py

Hello World from Python
```

</div>

/// tip | 팁

   */
  boolean containsValue(@CompatibleWith("V") @Nullable Object value);

  /**
   * Returns the value corresponding to the given row and column keys, or {@code null} if no such
   * mapping exists.
   *
   * @param rowKey key of row to search for
   * @param columnKey key of column to search for
   */
  @Nullable V get(
      @CompatibleWith("R") @Nullable Object rowKey,

                for (MetadataGraphEdge e : outs) {
                    sb.append("        to :  ").append(e.toString()).append('\n');
                }
            } else {
                sb.append("      no exit\n");
            }

            sb.append("-------------------------------------------------\n");
        }
        sb.append("=============================================================\n");

	if err != nil {
		return nil, err
	}
	defer func() {
		if debugReqs {
			_, ok := c.outgoing.Load(client.MuxID)
			fmt.Println(client.MuxID, c.String(), "Connection.Request: DELETING MUX. Exists:", ok)
		}
		client.cancelFn(context.Canceled)
		c.outgoing.Delete(client.MuxID)
	}()
	return client.traceRoundtrip(ctx, c.trace, h, req)
}

// Request allows to do a single remote request.

 *       java.util.function.Function} is accepted (for example {@link java.util.stream.Stream#map
 *       Stream.map}).
 *   <li><b>Do not</b> call {@link #doForward} or {@link #doBackward} directly; these exist only to
 *       be overridden.
 * </ul>
 *
 * <h3>Example</h3>
 *
 * {@snippet :
 * return Converter.from(
 *     Integer::toHexString,
 *     s -> parseUnsignedInt(s, 16));
 * }
 *

    throw new InvalidObjectException("Use SerializedForm");
  }

  /**
   * Not supported. Use {@link #toImmutableBiMap} instead. This method exists only to hide {@link
   * ImmutableMap#toImmutableMap(Function, Function)} from consumers of {@code ImmutableBiMap}.
   *
   * @throws UnsupportedOperationException always

   * @param array an array of {@code int} values, possibly empty
   * @param target a primitive {@code int} value
   * @return the least index {@code i} for which {@code array[i] == target}, or {@code -1} if no
   *     such index exists.
   */
  public static int indexOf(int[] array, int target) {
    return indexOf(array, target, 0, array.length);
  }

  // TODO(kevinb): consider making this public

        if (Files.isDirectory(filePath)) {
            filePath = filePath.resolve("index.html");
        }
        if (Files.exists(filePath)) {
            try (InputStream in = Files.newInputStream(filePath); ServletOutputStream out = response.getOutputStream()) {
                response.setStatus(HttpServletResponse.SC_OK);